Distinguishing excitatory and inhibitory transcallosal interactions.

人类的大脑分为两个半球，它们相互作用以处理信息并控制身体。大量的研究已经描述了两个半球的特化方式。例如，左半球在语言功能上占主导地位，而右半球在空间判断上占上级地位。然而，大多数人类认知需要两个半球的贡献，它们以部分合作和部分竞争的方式相互交流。了解这种交流是如何在两个半球之间发生的，对于开发以有益的方式调节大脑活动的新方法至关重要，例如通过非侵入性脑刺激。 最近，许多新的方法已经被开发出来，用一种叫做脑磁图（MEG）的机器来检测大脑的电活动。脑磁图以高的空间和时间精度记录神经元产生的电磁波。通过同时分析两个大脑区域的活动，研究人员可以检查信息在不同时间在它们之间传递的程度以及方向。我们实验室的研究表明，区分合作和竞争的相互作用是可能的，这可能表现在不同的大脑信号中。 为了验证对这些信号的分析，我们将利用一些众所周知的大脑不对称性，其中信息从大脑半球传递到另一个半球（合作互动），并且其中一个半球抑制另一个半球（竞争）。例如，左运动皮层控制身体的右侧，而右运动皮层控制身体的左侧。当有人移动右手时，他们的左侧运动皮层会通过脊髓向右手发送兴奋信号，但也会向右侧运动皮层发送抑制信号，以防止其干扰。通过测量手部运动过程中的电活动，并将其与其他已知的竞争措施进行比较，我们将验证使用新技术来检测竞争性互动。 另一种不对称发生在周边视觉。左脑接收来自右视野的视觉信息，反之亦然。由于左半球在语言方面占主导地位，因此呈现在左视野（到右半球）的词汇信息必须传递到左半球，但反过来的情况要少得多;另一方面，右半球在对面孔做出决定方面占主导地位，因此呈现在右视野（左半球）的面孔信息会以不同的方式传递到右半球。通过比较单词和面孔的相互作用，我们将验证使用新技术来检测两半球之间的信息不对称传输。

The human brain is divided into two halves, or hemispheres, which interact with each other to process information and control the body. A large amount of research has characterized the ways in which the two hemispheres are specialized. For example, the left hemisphere is dominant for language functions, while the right is superior at spatial judgments. However, most human cognition requires contributions from both hemispheres, and they communicate with each other in ways that are partially cooperative and partially competitive. Understanding how this communication happens between hemispheres is critical for the development of new methods to modulate brain activity in beneficial ways, such as through noninvasive brain stimulation. Recently, many new methods have been developed to detect the brain's electrical activity with a machine called magnetoencephalography (MEG). MEG records the electromagnetic waves generated by neurons with high spatial and temporal precision. By analyzing the activity in two brain regions simultaneously, researchers can examine the degree to which information is transferred between them at different times, and in which direction. Our laboratory's studies have suggested that it may be possible to distinguish cooperative and competitive interactions, which may manifest in different brain signals. To validate the analysis of these signals, we will take advantage of some well-known asymmetries of the brain, in which information is transferred from brain hemisphere to the other (a cooperative interaction), and in which one hemisphere suppresses the other (competition). For example, the left motor cortex controls the right side of the body, and the right motor cortex controls the left side of the body. When someone moves their right hand, their left motor cortex sends an excitatory signal to the right hand via the spinal cord, but also sends an inhibitory signal to the right motor cortex to prevent it from interfering. By measuring electrical activity during hand movements, and comparing it with other known measures of competition, we will validate the use of new techniques to detect competitive interactions. Another asymmetry occurs with peripheral vision. The left side of the brain receives visual information from the right visual field, and vice versa. Because the left hemisphere is dominant for language, information about words presented in the left visual field (to the right hemisphere) must be transferred to the left hemisphere, but the reverse occurs much less. On the other hand, the right hemisphere is dominant for making decisions about faces, so information about faces presented to the right visual field (left hemisphere) is differentially routed to the right hemisphere. By comparing interactions for words and faces, we will validate the use of new techniques to detect asymmetrical transfer of information between the hemispheres.